//引入events模块
var events = require('events');
//创建 eventEmitter对象
var eventEmitter = new events.EventEmitter();

//创建事件处理程序
var connectHandler = function connected() {
    console.log('连接成功');

    //触发data——received事件
    eventEmitter.emit('data_received');
}

//绑定 connection 事件处理程序
eventEmitter.on('connection', connectHandler);

//使用匿名函数绑定data_received事件
eventEmitter.on('data_received',function () {
    console.log('数据接收成功.')
});

eventEmitter.emit('connection');

console.log("程序执行完毕")
